Mystery surrounds the death of a couple whose bodies lay undiscovered in their Ballycastle home for several weeks.

Police found the remains of Rita (79) and Kenneth (68) Boughey when they forced their way into their house on Thursday evening after being contacted by the couple's worried son, who said he was unable to locate his parents.

Carbon monoxide poisoning is one line of inquiry into the deaths, however police said that there was no detection of the gas when they entered the couple's home.

They would not say if there were any signs of a disturbance or break-in at the property.

Officers are hoping that the results of post-mortem examinations, which were carried out yesterday, will help determine what happened.

Until then the deaths are being treated by police as "unexplained".

Mr and Mrs Boughey were originally from Liverpool. They lived in Spain for a while before settling in Northern Ireland around 10 years ago.

Neighbours in the quiet development where they lived knew little about the very private couple. Nobody even knew their names.

However, many were upset that they had failed to realise something terrible had happened on their doorsteps.

"I wish I had paid more attention to what was happening. I can't believe they have been lying dead for several weeks. I'm upset to think they needed help and not one person in here knew. I didn't even know their names," a neighbour said.

"The last time I saw them was about two months ago. It never even occurred to me something could be wrong," another neighbour added.

One neighbour said that the couple's son had called at a number of homes on Thursday asking if anyone had seen his parents recently.

"They were very quiet. I can't recall seeing many visitors to the house even. Their blinds were often pulled. Their son arrived yesterday (Thursday) asking if anyone had seen his parents recently. When he realised they had not been seen for some time, he raised the alarm with police I think," she added.

Officers forced their way into the house in The Abbey estate at 8.30pm and discovered the bodies.

The Fire and Ambulance Services also attended the scene, which was yesterday cordoned off with police tape.

Forensic officers carried out investigations at the property on Thursday night and into yesterday morning.

A police car guarded the property throughout yesterday as inquiries continued.

Chief Inspector Mark McClarence said officers were keeping an open mind about the cause of death.

"There has been a lot of speculation about carbon monoxide. We are remaining very open-minded. The Fire Service attended to check the property as that was a consideration at the time, but at that stage it was safe for police to enter.

"We do appreciate the bodies were there for some time and it (carbon monoxide) may have been a factor at that time." Mr McClarence would not say if there were any signs of a break-in or disturbance at the property.

"The scene is still being fully examined. A lot of inquiries are ongoing," he said.

"At this time the deaths are being treated as unexplained. The post-mortem will determine how the investigation progresses."

Police are keen to establish a timeline around how long the bodies were in the house and have asked people to come forward with information about the last time the couple were seen in public.

"I've spoken to a few of the neighbours in the area and they are all very shocked. It really is devastating," said Sinn Fein councillor Cara McShane.

"The couple very much kept themselves to themselves. People said they would have known them to see or wave to but that's it. The mood is very sombre. People are very upset that they didn't realise anything was wrong inside the house," she added.

SDLP councillor Donal Blaney added: "There is something very sad about all of this. That an elderly couple could lie dead for weeks without anyone knowing. My sympathies go out to their family and friends. It is shocking news."